Indexing device for performing operational tasks on a tool element

ABSTRACT

An indexing device for successively positioning a tool element relative to an apparatus adapted to perform a series of operational tasks on said tool element comprises a base, a reciprocally movable support mounted on the base, a fixing member adjustably mounted on the support for fixing the tool element thereto, a pivotable arm mounted to the base and extending between the support and the apparatus, an indexing abutment mounted on the arm and positioned thereon to contact a part of the tool element. The support is moved in a first direction to bring the tool element in a task performing position with the apparatus. The movable support has a pusher to contact the arm and to cause pivotal movement of the arm when the support is moved in this first direction whereby the arm and the abutment are moved away from the task performing position. Thereafter, the arm is returned to a subsequent task performing position when the support is moved in a second direction opposite the first direction.

FIELD OF THE INVENTION

The present invention relates to an indexing device for successivelypositioning a tool element relative to an apparatus adapted to perform aseries of operational tasks on the tool element.

In particular, the present invention relates to an indexing device forsuccessively positioning a saw blade relative to an apparatus adapted toperform a series of tooth grinding tasks on the saw blade teeth.

BACKGROUND OF THE INVENTION

Bench saw operators are dependent upon outside sources in order toperform certain operations, such as the resharpening of their sawblades. This situation generally entails that the operators hold uptheir decision on taking their blades out for resharpening so that theymay keep up with production. This has a direct impact on the quality ofthe work performed, as well as on the pleasure of doing it.

Furthermore, the useful life of a saw blade drops dramatically whenre-sharpening is unduly delayed, which translates into an economicallyharmful factor.

Existing saw blade resharpening machines are stable and heavy because ofthe high precision and severe work duty associated with the resharpeningprocess. These machines are therefore expensive and require asignificant floor space area.

Also, existing circular saw blade sharpening machines require a rathercomplex indexing mechanism to precisely position the blade teeth priorfor them to be moved towards the grinding wheel for adequate materialremoval.

Existing indexing mechanisms on most grinding machines use a movingelement which makes contact with the face of the tooth to be ground, anddisplaces it very precisely where it should be for the grinding wheel tomove in and remove a pre-determined amount of material (usually a fewthousands of an inch).

In view of the fact that the moving element makes contact with the faceof the tooth, as a starting reference, the moving distance has to beestablished according to a mathematical formula based on the saw bladediameter and the total number of teeth, before it is preset.

However, if a saw blade to be resharpened has a slightly damaged tooth(often the case), the preset moving distance of the moving element is nolonger appropriate, and the situation could be dramatic in a sense thatthe expensive diamond grinding wheel could be destroyed.

Most existing resharpening machines use this moving element conceptadvantageously in an automatic mode. However, because of its relativecomplexity, it is not appropriate for a manual and user friendlyoperation.

OBJECTS AND STATEMENT OF THE INVENTION

It is therefore an object of the present invention to provide a userfriendly indexing device for successively positioning a tool elementrelative to an apparatus adapted to perform a series of operationaltasks on the tool element.

The indexing device comprises:

-   -   a base;    -   a reciprocally movable support mounted on the base;    -   a fixing member adjustably mounted on the support for fixing the        tool element thereto;    -   a pivotable arm mounted to the base and extending between the        support and the apparatus;    -   an indexing abutment mounted on the arm and positioned thereon        to contact a part of the tool element;    -   means allowing the support to move in a first direction to bring        the tool element in a task performing position with the        apparatus;    -   the movable support having pusher means to contact the arm and        to cause pivotal movement of the arm when the support is moved        in the first direction whereby the arm and the abutment are        moved away from the task performing position; and    -   means for returning the arm to a subsequent task performing        position when the support is moved in a second direction        opposite the first direction.

In a preferred form, the present invention is to provide an indexingdevice for successively positioning a saw blade relative to an apparatusadapted to perform a series of tooth grinding tasks on the saw blade.

The indexing mechanism of the present invention is much simpler andeasier to operate by anyone using a manually operated grinding machinethan that which exists at present.

There is no indexing adjustment required, regardless the blade diameteror the number of teeth (the amount of material to be removed or groundis factory preset).

In the case of a slightly damaged tooth, it can be repaired by going inwith successive passes until it recovers its sharp edges characteristicsagain.

Another advantage of the design of the present invention is that theindexing abutment is moved away ahead and slightly behind the grindingwheel, at a faster speed than that of the blade due to the geometry ofthe arm and pivot shaft on the forward stroke of its feed lever. Theabutment is automatically returned to its previous position on thereturn stroke of the feed lever with the help of a tension spring force.

A button head type bolt is a most convenient way to move the abutmentaway and to repeatedly position the abutment at the end of the returnlever stroke as well as to accommodate for the complex relative slidingmovement between the abutment arm and the movable support, as well as tostop the displacement of the movable support on its return stroke.

Other objects and further scope of applicability of the presentinvention will become apparent from the detailed description givenhereinafter. It should be understood, however, that this detaileddescription, while indicating preferred embodiments of the invention, isgiven by way of illustration only, since various changes andmodifications within the spirit and scope of the invention will becomeapparent to those skilled in the art.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a top perspective view of an indexing device made inaccordance with the present invention when used in a blade grindingoperation;

FIG. 2 is an enlarged top view of part of the indexing device;

FIG. 3 is an enlarged elevational view of part of the indexing device;

FIG. 4 is a top perspective view similar to FIG. 1 but showing theindexing device in a non-indexing position;

FIG. 5 is an enlarged top view of part of that shown in FIG. 4; and

FIG. 6 is an enlarged elevational view of part of that shown in FIG. 4.

DESCRIPTION OF A PREFERRED EMBODIMENT

FIG. 1 shows the present invention used in the successive positioning ofthe teeth of a blade 10 relative to a blade grinding apparatus 12.However, the present invention should not be limited to this particularfunction. Hence, in a broader sense, the invention concerns an indexingdevice for successively positioning a tool element to an apparatusadapted to perform a series of operational tasks on the tool element.

Also, in FIG. 1, a table 14, which may be the top surface of aconventional bench saw, is particularly configured to enable theoperation of the blade grinding apparatus 12. However, a detaileddescription of this configuration is not essential for the understandingof the present invention; on the other hand, such mounting can be foundin applicant's co-pending U.S. patent application Ser. No. 10/695,598filed Oct. 28, 2003.

Referring also to FIG. 2, the indexing device of the present inventioncomprises a base 16 on which is mounted a reciprocally moveable support18, to which is mounted a fixing plate 19 displaying a longitudinal slot20 and a pair of arcuate slots 22 and 24. A fixing knob 26, providedwith a stem (not shown) extending through the center opening 28 of theblade 10 and received into the slot 20, serves to fix the blade 10 tothe support member 19.

Referring additionally to FIG. 3, to the front end of the base 16 isfixed a bracket 29 supporting a pivot shaft 30. A pivot lever 31 isfixedly mounted to the pivot shaft 30 and has its lower end 32 adaptedto receive one end of a spring 34 (the function of which will bedescribed later). The opposite end of the spring 34 is connected to thebase at 36. The pivot shaft 30 extends horizontally and obliquelyrelative to the base and supports, at its opposite end, a perpendicularextending arm 40. The top face of arm 40 bears an indexing abutment 42.As can be seen, in FIG. 2, the indexing abutment 42 is adapted tocontact face 44 of a blade tooth 46 of the blade 10.

The movable support 18 displays, at its front end, a pushing member 48,adjustably screwed and locked with lock nut 50. A large washer 52 isalso simultaneously locked, between nut 50 and the front end of movablesupport 18. Washer 52 acts as a stopper, as it contacts the front face54 of base 16, on the return stroke of movable support 18, for preciseand repetitive positioning of abutment 42, in prepartion for the correctpositioning of the subsequent tooth to be ground.

Pushing member 48 is adapted to contact the arm 40 and to cause it topivot about the axis of shaft 30. As can be seen in FIG. 2, theactuation of the pushing member 48 causes the arm 40 and its abutment 42to move to the right and to clear the grinding wheel 56, due to theangular positioning of shaft 30. As can be seen in FIG. 3, the abutment42 will always move at a faster speed than the speed of the movablesupport 18, because the abutment 42 is located on a longer radius.

Hence, as illustrated in the drawings and with reference to theparticular embodiment of the present invention used in association witha saw blade resharpening apparatus, the abutment 42 serves to properlycontact and position a saw blade tooth to be ground (the saw blade isrotated manually until the tooth to be ground touches abutment 42) withrespect to the grinding wheel 56. Once this is achieved, an overheadsecuring member 58 is manually screwed to contact the blade 10 so thatthe grinding operation may begin without vibration. By actuating a lever60 connected to the movable support 18, pusher 48 causes the arm and itsabutment 42 to be angularly pivoted (such as shown in FIGS. 4, 5 and 6)with respect to the axis of the grinding wheel 56. Once the grindingoperation is terminated for one blade tooth and during the return strokeof the lever 60, while spring 34 causes the shaft 30 to pivot back andthe arm 40 to return to its initial position, the overhead securingmember 58 is manually loosened and the saw blade rotated manually by onetooth, before the abutment 42 reaches its final position again, at whichtime the adjacent tooth can be brought to contact it, in preparation forthe next sequence.

The pushing member 48 has a frusto-spherical shape which is required asa result of the relative and complex movement between the support 18 andthe arm 40.

Although the invention has been described above with respect to oneform, it will be evident to the person skilled in the art that it may bevaried and refined for similar operational task. It should therefore beunderstood that the present invention should not be limited ininterpretation, except by the terms of the following claims.

1. An indexing device for successively positioning a tool elementrelative to an apparatus adapted to perform a series of operationaltasks on said tool element, comprising: a base; a reciprocally movablesupport mounted on said base; a fixing member adjustably mounted on saidsupport for fixing said tool element thereto; a pivotable arm mounted tosaid base and extending between said support and said apparatus; anindexing abutment mounted on said arm and positioned thereon to contacta part of said tool element; means allowing said support to move in afirst direction to bring said tool element in a task performing positionwith said apparatus; said movable support having pusher means to contactsaid arm and to cause pivotal movement of said arm when said support ismoved in said first direction whereby said arm and said abutment aremoved away from said task performing position; and means for returningsaid arm to a subsequent task performing position when said support ismoved in a second direction opposite said first direction.
 2. Anindexing device as defined in claim 1, wherein said pusher meanscontacts said arm at a location to cause greater displacement of saidabutment than that of said support.
 3. An indexing device as defined inclaim 1, wherein said pusher means consists of a frusto-spherical head.4. An indexing device as defined in claim 3, further comprising meansfor causing translational displacement of said support.
 5. An indexingdevice as defined in claim 1, wherein said arm is mounted to said baseby means of a pivotal link and wherein said returning means consists ofa spring having one end connected to said link and an opposite endconnected to said base.
 6. An indexing device as defined in claim 1,further comprising means for fixing said tool element to said fixingmember.
 7. An indexing device for successively positioning a saw bladerelative to an apparatus adapted to perform a series of tooth grindingtasks on said blade, comprising: a base; a reciprocally movable supportmounted on said base; a fixing member adjustably mounted on said supportfor fixing said blade thereto; a pivotable arm mounted to said base andextending between said support and said apparatus; an indexing abutmentmounted on said arm and positioned thereon to successively contact teethof said blade; means allowing said support to move in a first directionto bring said blade in a tooth grinding position with said apparatus;said movable support having pusher means to contact said arm and tocause pivotal movement of said arm when said support is moved in saidfirst direction whereby said arm and said abutment are moved away fromsaid grinding position; and means for returning said arm to a subsequenttooth grinding position when said support is moved in a second directionopposite said first direction.